I tried to use a regular expression to generate a value for a custom dimension from the URL.
Here I read that I should use a Regular Expression testing tool like https://regex101.com/ to prevent mistakes.
But my impression is that, for example, escaping an URL slash in Matomo is wrong and I have to do without backslashes instead.
URL: /de/area1/xyz.html or /de/area2/xyz.html
To extract area1 or area2 I have following regex:
Correct Regex: \/de\/([a-zA-ZäöüÄÖÜ-_]+)
Matomo regex that delivers the desired results: /de/([a-zA-ZäöüÄÖÜ-_]+)
Is the documentation with the reference to regex101.com not precise enough or is the regular expression implementation in Matomo different?
Thank you for creating the issue @utrautmann Likely this needs to be mentioned in the FAQ and is expected behaviour.
This is kind of documented in https://matomo.org/faq/how-to/custom-dimensions-extractions/
Developers Note: You don’t need to escape forward slashes as Matomo does this for you automatically. e.g. use /news/ instead of \/news\/
One easy solution in regex101 is to set the delimiter left of the regex to something else than / (this way one doesn't need to escape it there just like in Matomo)